Module 1 Introduction To Pharmacology Flashcards
What is pharmacology?
The study of biological effects of chemicals
What are drugs?
Chemicals that are introduced into the body with the intent to cause a change
What is pharmacotherapeutics and what is its focus?
- The use of drugs to treat, prevent, and diagnose disease
- focus is on:
1.) drugs effect on the body
2.) body’s response to the drug
What is a controlled substance?
Any drug with an abuse potential (physical or psychological dependence)
DEA (drug enforcement agency)
Monitors the prescription, distribution, storage, and use of controlled substance drugs in an attempt to decrease substance abuse
Schedule l (c-1)
Define and examples
- No currently accepted medical use and a high potential for abuse
- marijuana, heroin, mescaline, lysergic acid diethylamide (LSD), methylenedioxymethamphetamine(MDMA)
Schedule 2 (c-2)
Define and examples
- High potential for abuse
- possible severe psychological or physical dependence
- fentanyl, hydromorphone, methadone, morphine, methamphetamine
Schedule 3 (c-3)
- define and examples
- Moderate to low potential for physical and psychological dependence
- still potential for abuse
- anabolic steroids, hydrocodone
Schedule 4 (c-4)
- define and examples
- Low potential for abuse and dependence
- Valium, Xanax, Darvon, phentermine
Schedule 5 (c-5)
- define and examples
-lowest potential for abuse
- Limited quantities of certain narcotics
- antidiarrheals, antitussives, analgesics
Drug use during pregnancy
- No drug is “safe”
- benefit outweighs the risk
Teratogenicity
- Adverse effects on the fetus
Old categories of drug risk classification
A, B, C, D, X
New risk classification
- Pregnancy
- lactation
- reproductive potential
Brand name drug characteristics (5)
- Name given by drug company once the drug is approved by the FDA
- companies research, test, and manufacture drugs
- more expensive
- drug formula is patented
- Insurance companies may not cover brand medications
Generic name drug characteristics(6)
- Original name given to the drug when it was submitted to the FDA for approval
- companies only manufacture drugs
- significantly less expensive
- same active ingredients
-Most states require generic drugs - generic drugs are safe
What are prescription drugs?
- Requires an order/prescription by a licensed provider
What are OTC drugs?
- Over-the-counter drugs
- available without a prescription for self-treatment
- are safe when taken as directed
- behind the pharmacy counter
OTC drug concerns(4)
- mask signs and symptoms of underlying disease
- can interact with Rx drugs and interfere with drug therapy
- serious overdoses can occur if not taken as directed
- patients often do not consider these drugs, so they do not report taking them
What are pharmacodynamics?
- How the drug affects the body
-The d in dynamics stands for drug (memory technique)
What are pharmacokinetics?
- How the body acts on the drug
What are the 4 mechanisms of action (MOA)
- Receptor action
- physical action
- act on other chemicals in the body
- enzyme/metabolic action
Define receptor action
-act on receptor sites located on the cell membrane
- agonist or antagonist
- agonist: birds to receptor site to increase or stimulate normal response
-Antagonist: binds to the receptor site to depress, block, or slow normal response
Define physical action
- Changes the physical properties of cells or body fluids
- damage the cell wall or alter pH
Define “act on other chemicals in the body”
- Creating chemical reactions
Define enzyme/metabolic action?
- Processes in the body requiring multiple steps to have an effect
- drugs can interfere with one of the steps by stoping, delaying, or speeding it up
Define “timing of drug action”
-onset, peak, duration
Define “critical concentration”
- Amount of drug needed to cause a therapeutic effect
Define “loading dose”
- Higher dose then that normally used for treatment
- recommended dosing schedule is followed once critical concentration is reached
Define “dynamic equilibrium”
- The actual drug level in a person’s body
Define “therapeutic index”
- Ratio comparing the blood concentration at which a drug becomestoxic with the concentrationat which the drug is effective
List the steps in which the body processes drugs
1.)absorption
2.)distribution
3.)metabolism (biotransformation)
4.)excretion
When does the process of absorption start and end?
- Starts when the drug enters the body
- ends when the drug reaches the circulating fluids and tissues
Types
of absorption
1.)passive diffusion
2.)active transport
3.)filtration
What are the main factors that influence absorption?
- Route
- solubility
-Tissue perfusion - ionization
- size
What is the fastest route for absorption?
- IM/IV
What allows the best solubility?
- Water and lipid soluble best
Tissue perfusion necessary for absorption
- tissue performance needs to be adequate (when supply meets demand)
Ionization needed for absorption
- No charge is the best ionization for absorption
What is the best size of molecules to absorb?
- The smaller the faster they will be absorbed
Movement of drug distribution
- The movement of drug through systemic circulation to the body’s tissues
- depends on the same factors as absorption
What are the components of distribution?
- Solubility (water and fat)
- ionization (no charge)
- tissue perfusion (adequate)
-protein-binding - blood-brain barrier(BBB)
- placenta and breast milk
Protein-binding with distribution
- Difficult for drug to cross the cell membrane
- Only “free” particles cause a therapeutic effect
-Tightly bound versus loosely bound
-Competition for protein-binding sites - Most drugs are bound to proteins in order to travel through the bloodstream
-The more tightly a drug is bound to the protein,the longer it takes for the drug particles to get free to enter the cell membrane - If it can’t get free from the protein binding sitethen it can’t work on the tissues.
-“Loose bound” means that they act faster and are excreted faster
What is the blood-brain barrier (BBB)?
- A protective mechanism to keep bad things out of the central nervous system and particularly the brain
- Drugs must be lipid soluble in order to enter BBB
- If infection gets bad enough, protein bound drugs will be let through
What is drug metabolism?
-The process by which drugs are changed to less active chemicals
-Another way fur the body to get rid of foreign or toxic substances
What is the organ responsible for drug metabolism?
- The liver
What is another name for drug metabolism?
- Biotransformation
What is the first-pass effect?
- Drugs that are administered orally are absorbed through the small intestine and then go into the portal vein then to the liver where liver enzymes break the drug into metabolites.
- The majority of metabolites are deactivated and then excreted
- What is left after the first pass effect is transported throughout the body via the circulatory system to the target tissues
What is parenteral administration?
- Drugs given with an IV or injection reach the tissues without going to the liver. (Reason for lower dosages)
- No first pass effect
- Still metabolized in the liver
What is the hepatic enzyme system?
- There are enzymes inside the liver cell that are responsible for metabolism of the drug
- Cytochrome p450 is the enzyme that is frequent
-Different drugs are metabolized by different enzymes
What is enzyme induction?
- When a drug is metabolized by a particular enzyme system, the presence of that drug in the system causes an increase in that enzyme system activity
- An increase of enzyme activity results in an increase in the metabolism of the drug so its inactivated and excreted more quickly.
What occurs if the drug inhibits the enzyme?
-The drug will not be broken down which is what’s needed for excretion. This can cause a drug to buildup in someone’s system and reach a toxic level
- if two drugs are metabolized by the same enzyme system then they should not be taken together because the will be metabolized too quickly and be less effective
Define drug excretion and the organ responsible?
-The removal of the drug from the body
-Kidneys
List some of the routes of excretion other then the kidneys
- Skin
-saliva
-lunges
-Bile - feces
What is glomerular filtration?
- Excretes water soluble drugs
- Water and water soluble components pass from the blood into the renal tubule
What is active transport?
- Excretes not water soluble drugs
- exchanges the drug molecules for either acid or bicarbonate molecules
- always consider a patient’s renal functions
Define half-life
- The time it takes for the amount of drug in the body to decrease to one-half (50%) of the previous dose
List factors influencing drug effects (10)
- Weight (average dose is based off of 150 pounds)
- Age (younger means faster metabolism; older means slower metabolism)
- Gender (males have more vascular muscle, IM medications will be seen sooner)
(Females have more fat cells, drugs that deposit fat may have prolonged effects) - Physiological factors (hydration and electrolyte imbalance)
- Pathological factors (the disease the drug is intended to treat)
- Genetics
- Immunological factors (allergies to drugs because of antibodies that develop to drug proteins)
- Environmental factors (atmosphere and mood)
- Tolerance
- Accumulation
List the four drug interactions
-Interaction when two or more substances are taken together
-Drug- Drug or Drug-Alternative Therapy Interactions
- Drug-Food Interactions
- Drug-Laboratory Test Interactions
When can the interaction of two or more substances taken together occur?
-At the site of absorption, distribution, biotransformation, excretion, or the specific site of action
- Example: Patient takes tetracycline (antibiotic)
with dairy products, the drug is not absorbed resulting in a decreased therapeutic effect
- Can also see a increase or decrease in therapeutic effect
Define drugs with narrow margins of safety
- The difference between the dose required to produce the therapeutic effect and the dose that would cause harm
What does drug-drug or drug-alternative therapy interactions include?
- Prescription drugs
- over-the-counter drugs
- herbal treatments
- supplements
- vitamins
When does drug-food interactions occur?
- When they are in direct contact in the stomach
- many drugs cannot be taken with grapefruit juice at all!!
- oral medications are typically best to take on an empty stomach
What are drug-laboratory test interactions?
- when the administration of certain drugs may alter test results
How can you ensure getting the optimal therapeutic effect?
- Be knowledgeable about the medications being administered
- make sure you have a full medication history on patients
- specifically ask patients about herbal supplements, vitamins, and OTC medications
- avoid problems before you have to treat problems
- physical exam
Define adverse effects?
- Undesired effects that maybe unpleasant or dangerous
- other effects besides the intended therapeutic effect
-Mild, moderate, severe - not taking the correct dose
- Patient sensitivity
What are the nursing responsibilities for adverse effects?
- Stay alert and monitor for drug reactions
- teach patient and families about what signs and symptoms of drugs taken may be
- interventions to prevent and manage adverse effects
Identify the 3 types of adverse effects
- Primary actions
- secondary actions
- drug allergy
What causes primary actions?
-too much of the desired effect (overdose)
- sensitivity, weight, age, underlying conditions, taking incorrect dose
How do you treat primary action adverse effects?
-decrease the dose
- monitor the patient closely for effects
Define secondary actions and example
- Effects on the body that are not the intended, therapeutic effect
- example: narcotics are used to manage pain. Many patients experience constipation due to the GI motility. Constipation is not the intended effect.
How can you decrease secondary action adverse effects?
- Possibly decrease the dose
- give interventions to manage effects (increase liquid intake, increase fiber for constipation)
What are drug allergy and hypersensitivity reactions?
- When antibodies are formed to a particular drug
- cross allergies may occur to drugs within the same class
- experiencing and not liking side effects is not the same as drug allergy’s
What is the anaphylactic drug reaction?
- It involves the release of histamine
- mucous membrane swelling occurs and bronchi constriction
- It occurs in the body immediately
What is the assessment of anaphylactic drug reaction and what occurs?
-hives, rash
- troubles breathing
- changes in blood pressure
- dilated pupils
- diaphoresis (sweating)
- increased heart rate
- panic/impending down
- respiratory arrest
What are interventions for anaphylactic drug reactions?
-Stop drug
- epinephrine subcutaneously
- notify provider
- medic-alert bracelet
- epinephrine kit (epi-pen)
What are dermatologic reactions?
- Reactions that effect the skin
What dues the assessment for dermatologic reactions include?
-Assess the skin for rashes and lesions
- systematic effects: enlarged lymph nodes, fever, hepatomegaly (enlarged liver)
- stevens-johnson syndrome: rare but serious
What are interventions for dermatologic reactions?
- Severe cases: discontinue medication, give medications to treat
- mild cases: skin care; teaching; medications
What is stomatitis?
- Inflammation of the mucus membranes
What is the assessment for stomatitis?
- Look for gingivitis, glottis, difficulty swallowing, bad breath, pain in mouth/throat
What are interventions for stomatitis?
-frequent month care
- frequent, small meals with non-irritating funds
- dental consultation
- medications: antifungals, local anesthetic
What is a hepatic injury?
- An injury on the liver
- The liver metabolizes drugs
What is the assessment for hepatic injury?
- Effects to the central nervous system such as a fever or malaise
- abdominal pain or change in urine and stool
- jaundice
- changes in labs such as elevated liver enzymes, abnormal bilirubin levels, changes in clothing factors
What are interventions for hepatic injury?
- Discontinue the drug
- small frequent meals
- skin care, cool environment
What are renal injuries?
- An injury of the kidney
- kidneys excrete drugs
- impairment will cause a accumulation of the drug in the body
What is the assessment for renal injury?
-effects to the central nervous system such as fatigue, malaise, irritability.
- Rash
- edema (excess fluid)
- decreased UOP (urine output)
- changes in labs such as elevated BUN (creatinine), decreased HCT (hematocrit), or electrolyte imbalance
What are interventions for renal injury?
- Positioning (helps edema), diet/fluid restrictions, skin care, electrolyte replacement, rest
- May need dialysis
- discontinue medication
What is drug poisoning?
- A toxic effect of a drug
- damage to multiple body systems due to an overdose of a drug
- May result in death
How can drug effects harm both the CNS and PNS?
- Both are dependent on glucose, oxygen, and electrolyte balance which can be effected by drugs breaching the blood-brain barrier and harming the brain
What is the assessment of drug toxic effects on the Central nervous system?
- Confusion, delirium, hallucinations
- insomnia, drowsiness, bizarre dreams
- hyper or hypo reflexia (over or under active reflexes)
- numbness, tingling, paresthesia (abnormal sensation of skin)
- seizures
Interventions for toxic drug effects on central nervous system
- Safety measures to prevent injury or seizures
- Patient education on safety measures
- orientation as needed
- decrease dose or discontinue drug
What is teratogenicity?
- Drugs causing death or congenital defects on the fetus
- some drug effects are known and some aren’t
- benefit versus risk
What are the steps for nursing considerations/nursing process?
1.)assessment
2.) nursing conclusion
3.) planning (and prioritizing)
4.) implementation (of interventions)
5.) evaluation
Nursing process is also known as…?
Nursing considerations
Nursing conclusion is also known as…?
Nursing diagnosis
What history is gathered during the nursing assessment? (10)
- Medical conditions
- current drug use
- allergies
- finances
- literacy/education level
- culture
- understanding of disease and drug
- reactions
- social support
-Health-seeking behaviors
What is gathered during the physical assessment/exam of the assessment?
- Age
- weight
- side effects of medications
- Therapeutic effects
What is gathered for diagnostic tests during the assessment?
- Labs
- X-rays
- ultrasound
What are the three portions of the assessment?
- History
- physical examination/exam
- diagnostic tests
What two things must be identified during the assessment before administering medications?
- Contraindications
- Cautions
What are the two forms of contraindications?
- Absolute: life threatening, never administer
- Relative: benefit versus risk, contact provider
Define caution
- May administer with additional nursing considerations
What are the three aspects of the nursing conclusion?
- Nursing focused
- based on drug therapy
- personalize to the patient
What is included in nursing planning?
- Goals/outcomes: Response to medication, prevention/treatment of adverse effects, patient education
- Prioritize: having a therapeutic effect to the medications
What is included in nursing implementation?
- Drug administration: safety/prevention of errors
- Comfort measures: comfort measures, lifestyle modifications, placebo effect
- Patient and family education
What is included in the nursing evaluation?
- Patient response to the drug: therapeutic effects, adverse effects
- Effectiveness of medication education
- Effectiveness of comfort and safety measures
- Compliance with regimen
What are the 5 nursing responsibilities?
1.) administer drugs
2.) assess drug effects
3.) intervene when adverse effects occur
4.) provide patient teaching
5.) monitor to prevent medication errors
What are the ten “rights” of the nurses rule?
1.) right patient
2.) right drug
3.) right reason
4.) right storage
5.) right route
6.) right dose
7.) right preparation
8.) right time
9.) patient education
10.) right documentation
